A conventional sewing machine or overlock sewing machine (hereafter “sewing machine”) that can form intermittently gathered seams during a sewing process has been widely known. According to this type of sewing machine, the intermittently gathered seams can be formed by temporally differentiating a cloth feeding amount of a main feed dog from a cloth feeding amount of a differential feed dog during the sewing process.
In more detail, the sewing machine is provided with a needle bar that reciprocates in an up and down direction towards a work cloth plate. A needle firmly supported by a tip end of the needle bar is adapted to go through a center hole of a throat plate. The main feed dog and the differential feed dog are arranged at a far side of the center hole and at a near side thereof. Each amount of movement of the main feed dog and the differential feed dog can be adjusted and controlled by use of an electric driving power source such as a pulse motor. Therefore, the cloth feeding amount of the main feed dog and the differential feed dog can be controlled in response to the activation of the pulse motor.
Still, another conventional sewing machine has been manufactured, which can finish seams by minimizing a moving amount of a feed main dog during a sewing process or after stopping the operation of the sewing machine. In this case, the moving amount of the main feed dog is minimized while maintaining a relative ratio between a cloth feeding amount of the main feed dog and a cloth feeding amount of a differential feed dog.
Japanese Laid-Open Patent Publication No. 1986-92693 (pp.2–13, FIG. 3) describes a method of forming intermittently gathered seams on a work cloth and an apparatus for forming the same. Further, Japanese Laid-Open Patent Publication No. 1981-163689 (pp. 2–4, FIG. 2) describes a sewing machine capable of adjusting a feeding amount of a feed dog. The sewing machine with a feed regulating function can change seams by differentiating a cloth feeding amount of a main feed dog from a cloth feeding amount of a differential feed dog at an intended timing during a sewing process.
According to JP 1986-92693, as illustrated in FIG. 13 of the present specification, a sewing machine main body M houses a regulating mechanism including the main feed dog, the differential feed dog, and a pulse motor. A control box C is provided separately from the sewing machine main body M and houses a control circuit, an operating portion and a display portion together. The control circuit memorizes and calls several types of control patterns for controlling or changing the feeding amount of the differential feed dog in response to the predetermined number of stitches. The operating portion selects, modifies, and sets any one of the memorized control patterns. The display portion displays information on the selected control pattern.
As illustrated in FIG. 13, the sewing machine main body M and the control box C are assembled with a distance therebetween. Therefore, the entire sewing system is very large and would not be appropriate for use at home. Further, the sewing machine main body M that actually forms stitches is positioned at a distance from the operating portion. Therefore, there are still issues for both operating performance and safety while operating the operating portion.
According to the sewing machine with the feed adjusting function, the moving amount of the differential feed dog is controlled in response to a command generated by depressing a foot pedal. However, a home sewing machine is generally operated by use of a foot pedal or a speed controller. Therefore, it may be difficult to operate plural foot pedals, and each foot pedal may be operated unnecessarily by mistake. This may badly influence accessibility of the operating members.
A need thus exists for providing an improved home sewing machine capable of changing a first sewing pattern to another sewing pattern while performing the first sewing pattern. The present invention also enables the home sewing machine to be more compact and to be operated with improved accessibility to an operating member while achieving improved safety.